M1 Rifle front sight misalignment

[IronsightsRifleman]

I took my new CMP Special to Angeles yesteday. It's really a beauty to fire and I couldn't be happier with it except that the front sight is way off. It took me a dozen rounds to get on paper, which I finally did through trial and error of aiming in various offset direction. It's shooting about 14 MOA to the left, although the elevation is near perfect. It's hard to tell with the naked eye but with the camera you can see that the front sight is not set properly. My plan is to use a boresight laser to get the front sight alignment corrected coarsely. I'll then follow up with fine tuning on my next range trip.
I certainly didn't let the misalignment spoil my day, and we made a game out of shooting targets off hand while aiming at the dirt!

[M1A Rifleman]

The Military way to zero an M1 is to set the rear sight windage to 0, and adjust the front sight left or right to get on paper. As long as the front sight does not hang over the base, it was considered fine. From you pick, it looks OK. For me, I center the front sight and adjust the rear as needed.

[sofbak]

Center your front sight on the gas cylinder (by eyeball or caliper, or your choice).

Unscrew the rear sight tension nut inside the windage knob (yeah that split cylinder in th windage knob). Unscrew the windage knob from the elevation pinion stem.

Center the rear sight via the mark on it vs the marks on the receiver.

Screw the windage knob back on to the sight base until all the slack/clearance between the windage knob and the sight ear on the right of the receiver is gone.

Re-intall/screw in the the tension nut.

Re-zero on the range.

[kendog4570]

Your front is not exactly centered on its base, but not out of spec. You have 14 minutes of wind on the rear, from mechanical zero? Which way?

[IronsightsRifleman]

Your front is not exactly centered on its base, but not out of spec. You have 14 minutes of wind on the rear, from mechanical zero? Which way?

With the rear windage adjustment at center, the projectiles impact 14 inches left of bull from 100 yards range.

[kendog4570]

14 minutes is a bunch. Could be a stack up of things. Misaligned parts, barrel not indexed properly, sight base not true to the splines in cylinder and/or barrel, front sight crooked or bent, rear sight funky. A little bit of everything. Contact CMP and see what they say.
Plz dont take this wrong, are you aligning the sights correctly? Correct, centered sight picture?

[IronsightsRifleman]

Plz dont take this wrong, are you aligning the sights correctly? Correct, centered sight picture?

Fair question. I had no problem with my M1 Carbine with similar sights. My friends had the same problem with the Garand that I did. It's the gun.

[smoothy8500]

the projectiles impact 14 inches left of bull from 100 yards range.

The FS will need to move Left (towards the bullet impact). Each .004" of FS movement equates to 1" movement of bullet impact. Looking at your picture of the FS, it already looks like it was initially too far to the right.

You'll need about .056" of movement. Get a sharp pencil and make a vertical line on the FS and the dovetail before loosening the screw so you know how far to move it. It will probably be right on the Left edge of the base when done.

[kendog4570]

With a 28" M1 sight radius, a 1 moa sight correction is closer to .008". .0078" to be exact.

NO standard 1 minute M1 or M14 sight tracks exactly that amount for each click. Mount a dial indicator on one and put wind on and off and you will see what I mean. Even take the slop out of the base with your finger when turning the wind knob. Sloppy, cast aftermarket "NM" ones are not much better.


Send it back. You will most likely wind up with a better than average "special".

[newbutold]

Would a Wyoming Sight Drifter help?

[slamfire1]

I cannot think of a M1 or M1a that I owned that did not need the front sight to be moved in one direction or another to get my rear sight perfectly zero'd.



I will recommend you check the tightness of the gas cylinder with the gas cylinder lock and screw installed. Does it wobble? I peened the splines, added epoxy glue, and drove the gas cylinder on. and left it there till the barrel shot out. Of course I took the lock screw off to clean the inside of the gas cylinder, but I left the gas cylinder in place. A tight fit is absolutely critical for any accuracy.

Check the wobble on the rear sight aperture. If the rear sight wobbles, you either have base track cuts , or a worn out aperture spring. If a new spring does not fix things, might as well as try to find a NM base and slide aperture as a set. Dee was a Korean War veteran, was on a Divisional rifle team. He told me the rifle he shot, the rear aperture was so loose in the slide he stuffed match sticks in the cuts to keep the aperture from teeter tootering!

I have several match Garands where the front sight is just on the edge of the sight base. And I say, so what! As long as the rear sight base is centered, then everything is OK.

Properly match bedded, match barrel, and tight sights, a Garand can shoot very well.

[hambam105]

I took my new CMP Special to Angeles yesteday. It's really a beauty to fire and I couldn't be happier with it except that the front sight is way off. It took me a dozen rounds to get on paper, which I finally did through trial and error of aiming in various offset direction. It's shooting about 14 MOA to the left, although the elevation is near perfect. It's hard to tell with the naked eye but with the camera you can see that the front sight is not set properly. My plan is to use a boresight laser to get the front sight alignment corrected coarsely. I'll then follow up with fine tuning on my next range trip.
I certainly didn't let the misalignment spoil my day, and we made a game out of shooting targets off hand while aiming at the dirt!

Wait for the flash...Wait...Look Closer...Hold it....

[IronsightsRifleman]

Would a Wyoming Sight Drifter help?

The front sight of a Garand is held on the dovetail by a tension screw which, when loosened, allows the sight to drift effortlessly. So in this case, no. It's an interesting suggestion, though.

[IronsightsRifleman]

Several folks in the posts above have mentioned the rear sights. I believe the rear sights are fine as the top scale centers on the bottom alignment mark and there are an equal number of clicks to the full left and full right windage stops. Am I missing something?

[IronsightsRifleman]

I cannot think of a M1 or M1a that I owned that did not need the front sight to be moved in one direction or another to get my rear sight perfectly zero'd.

I will recommend you check the tightness of the gas cylinder with the gas cylinder lock and screw installed. Does it wobble? I peened the splines, added epoxy glue, and drove the gas cylinder on. and left it there till the barrel shot out. Of course I took the lock screw off to clean the inside of the gas cylinder, but I left the gas cylinder in place. A tight fit is absolutely critical for any accuracy.

I have several match Garands where the front sight is just on the edge of the sight base. And I say, so what! As long as the rear sight base is centered, then everything is OK.

The gas cylinder seems to have no play in it. Also, the spines on the barrel don't appear to be mis-indexed, at least not that I can notice. I did remove the gas cylinder once to better finish the upper hand guard. The fit was close, but not so tight that it had to be driven on, just given a few light tape with my hand.

I won't get to the range again for a few weeks, but when I do I'll see how far I have to move the from sight to get it zeroed and report back.